hamilton



Dec. 16, 1930. w; F, HAMlLToN 1,785,411

' IGNITION SYSTEM Filed Jan. 10. 1929 Patented Dec. 16, 1930 UNITED vsierras PATENT OFFICE WILLIAM F. HAMILTON, or NEW Yonx, N. Y., AssIGNoRor ONE-HALF To FRANK s RoLLINs, oF NEW YORK, N. Y. i

IGNITIONl SYSTEM l y Application iled` January 10, 1929 Serial No. 331,496.

The present invention relates to ignition systems for internal combustion engines, and particularly to high tension ignition systems in which the breaking of a primary circuit 5 induces a high potential into asecondary circuit, which causes the ignition spark to occur in the combustible mixture which is to be fired. The timing of the breaking of the primary circuit in such systems must be so ad- 1`0 justed as to cause the high tension spark to occur at the proper-moment in the compressed charge,in order to attain a good efficiency. In v engines of .more than one cylinder, it is furthermore necessary to distribute the ignition current 'in the proper order in the several cylinders. Apart from the requirement of correct timing and proper distribution, the nature of the spark discharge withincthe compressed mixture determines, to a considerable extent, the efficiency of combustion under the conditions of operation in internal combustion engines, and there is a certain relation between the timing-of the spark and the speed and load of the engine, which makes it nec-' 25 essai-y to vary the timing with different speeds and loads in the usual type of spark discharge employed in such engines.

In general, the. present invention provides for highly accurate timing of the spark, an improved method of spark distribution, and a simplified relation between ythe timing of the spark and the speed and load of the en- .vginel Thetiming of thel spark is accomplished directly byA primary circuit breakers actuated directly by theengine pistons, the distribution of the spark is likewise controlled directly by the pistons, and the. relation of the timing to the varying speed and load of the engine is advantageously maintained constant by reason of the nature of the spark discharge which is obtained in accordance with the invention. The apparatus employed in accordance with the invention represents a substantial simplification and saving in costA o f equipment as compared with the usual.-

systems, and offers greater accuracy and reliability of operation.

An embodiment of the invention is illustrated by way of example inthe accompanying drawing, in whichbreaker.

Figure 1 isa circuit diagram of the ignition system; y

Figure 2'is a vertical section through a primary circuit breaker and a spark lug electrode mounted in operative position a ove the piston; f

Figure 3 is a detail view, with part in verticalsection, showing one of the assembly units of a primary circuit breaker; and

Figure 4 isa similar View showing the other assembly unit of the primary circuit Referring to Figures 2, 3 and 4, 10 indicates the cylinder head disposed above the engine block 11 of, for example, a T-head motor. 12 indicates the top of a reciprocating-piston operating in the cylinder 13j The spark electrode in cylinderl is indicated at 14 as comprisingan L-shaped or otherwise laterally extended terminal dis osed in parallel relation and within spar ing distance of the piston at the top of the piston stroke. This electrode 14, apart from its particular shape asmentioned, may be mounted in a porcelain tube 15 in a manner well-known in the prevailing spark plu constructions,

and ypiston 12rep resents one of the spark .l

of the system.

gaps of the secondary high tension portion In a somewhat similar manner, the circuit breakers for the primary circuits of the transformer system are mounted over certain of the /pistons `12, as will`4 .be more fully explained, these circuit.; breakers comprising y 21 which extends downwardly through the', cylinder head 10 and across the compress/ien space to a point slightly below 'the top "of the piston throw so that as the piston Ico' passes through a flanged nipple 22 which is threaded into the cylinder head 10, and the Y upper end of the rod 20 is guided in a recess formed in the wall of an inverted cup-like member 23 which is internally threaded to be screwed on to the externally threaded cup lportion 24 of the nipple 22. These cup members 23 and 24thus forma closed housing for the upper end of the rod 21. and certain moving parts which will be explained. This enclosed lspace or chamber is entirely shut ol' from the atmosphere so that the necessity of packing around the rod 21 to avoid loss of compression is obviated. On account of the distance of this enclosed chamber from the firing chamber, the temperature to which the enclosed parts are subjected approximates that of the surrounding atmosphere, and does not approach that which occurs inthe combustion chamber. Within the cup 23 and cup 24 a perforated metallic disk or saddle 25 is supported on screws 26 which are insulated from the cup 23 by bushings 27 and adjustably fixed at suitable height by means of the nuts 28 and 29. The lead wire 30 coming from one side of the primary circuit is electrically connected to one of the screws 26 so that the saddle 25 constitutes one terminal of this circuit. The other terminal is formed by the flange or shoulder 31 which is provided on the rod or plunger 21 and is normally pressed resiliently injcontact with saddle 25 by the compression spring 32 which 1s confined between the shoulder 31 and the top wall of the cup 23. The perforation in saddle 25 is of such diameter as to .insure against making contact -with the plunger 21 except by the seating of shoulder 31 upon the saddle 25. The plunger 21 being guided at its upper end in the recess in the top of cup 23 and having a sliding lit in nipple 22, is movable only straight up and ldown under the displacing action of piston 12 and the return action of spring 32. Since the shoulder 31 is normallyI he'ld upon the saddle 25 byV the pressure of sprin 32, the primary circuit is normally close through this contact and through the contact of the plunger with parts grounded in the cylinder head. When the plunger 21 is elevated by the piston 12, shoulder 31 is lifted out of contact with saddle 25 so that the primary circuit'is opened. To insure the opening of this circuit at the proper moment, the cup 23 may be raised or lowered-on the cup 24,thusA carrying with it the assembly unit,-shown in Figure. 3, and causing the plunger 21to be .engaged by the piston 12 earlier or later while observing the effect upon the operation of the engine. Having been adjusted to proper position, the .cup 23 may be locked on cup 24 by tightening lock nut 33 against the` gasket 34 which at the same time seals the joint against-leakage. Figures 3 and 4 illustrate the two units which constitute the circuit breaking mecha nism and its means of mounting in the cylinder head. It will be noted that the moving parts of this mechanism are readily removable as a unit, and may be replaced when desired in much the same manner as the presentday spark plugs. The design illustrated is intended to permit the circuit breaker to be applied in the usual petcock opening in the cylinder head. Obviously, suitable provision for mounting the circuit breaker may be made at any other point where the plunger may be actuated bythe piston.

A further feature of the invention resides in the electrical system of wiring, incombination with the new circuit breaker and ignition electrode. A n embodiment of this circuit arran ement is illustrated by way of example in igure 1. In this diagram, the engine is presumed to have six cylinders of which cylinders numbered 1 and 6 move upv and down in unison, as do also cylinders 2 and 5 and cylinders 3 and 4. This arrangement 1s common in six cylinder motors. A

firing electrode, such as already described, .y

is provided for each of the six cylinders, and

one circuit breaker is provided for each pairof cylinders which move in unison as above mentioned. Cylinders 1 and 6, for example, have their individual lsparking electrodes which are connected to opposite ends of the secondary coil 3, this secondary circuitheing completed across the spark gapsto the respective pistons, so that the `spark gaps ofthe two cylinders are in series with each other. One of the circuit breakers is mounted over the piston in either cylinder No.' 1 or cylinder No. 6 of this pair, such circuit breaker being indicated in' Figure l at 40. 'lhis circuit breakercontrols the low of current through the primary circuit of coil 3, which circuit may be traced as follows: starting with battery 41, through ignition switch 42, variable resistance 43, parallel branch line 44, primary winding of coil 3, thence by primary lead 45 to circuit breaker 40 and, when the circuit at this point is closed, back to batter;1 by way of the cylinder head. The breaking of this primary circuit at the point 40 in Figure 1 causes an oscillatory current to occur in the circuit comprising coil 3 and condenser 46, which latter is grounded in the engine block or cylinder head. This oscillatory current induces into los .pleted its exhaust stroke. Under such conditions the hot exhaustE gases in, for example, cylinder N o. 1, are in a highly ionized state and offer little resistance to the passage of current across the gap, and thus the principal energy is discharged in cylinder No. 6 which is ready for iring. Since the spark passes between the piston and the spark elec-l trode, which present parallel surfaces to eachA other, the path of the spark will move laterally along the extended portion of the sparkelectrode to ignite the charge over an extended area. While it is not essential that the spark electrode be mounted in position `to cause the spark to` occur between this electrode and the piston, (since obviously the spark could be caused to occur between the electrode Vand any partof the engine block l within the combustion chamber), it is to be observed if drawn between the electrode and,l

` the piston the spark' will be stretched verti-l cally by the downward motion of the piston as the latter recedes, and consequently a travelling spark of greater eiiiciency will be obtained. In this connection, itis pointed out that the maximum rate of iame propagation is decreased, and the average time necessary for 'combustion of the mixture is also decreased by the i ition obtained from such a form of spark 'schar e. These two Afactors of maximum rate of ame'prpaga-l t1on and average time necessary Ifor c0mbus` tion of the mixture are variable in-a given motor,` and depend largely on the speed and load at which the motor is running. The maximum rate of flame Apropagation increases as the speed or the load is increased, whereas the time necessary for combustion of the mixture is decreased as the speed or load is increased. Dueto-,the accurate timing of the spark andthe character-of the spark discharge, obtained in accordance with the principles of this invention, it is unnecessary to advance or retard the s ark under varying conditions of speed and oad.

The pair of' cylinders, numbered 2 and 5, are provided with similar primary and sec- 'cndary circuits and their circuit breaker, as

are also the paired cylinders 3 and 4; and it is therefore unnecessary to repeat the description of these electrical connections.

In the construction shown and described, it

so that the primar will be observed that the primary' circuit. is normally closed throughl the circuit breaker' current will have time to build up to fu i strength between each closing "and opening thereof. At high motor speeds, there will thus be no danger of reduced energy supplied tothe secondary circuit. The make and break surfaces are of extended area and thus minimize pitting. By suitable adjustment of the position of the' saddle 25 in the cup 23, and the position of cup 23 on cu 24, not only the .timing of the circuit brea ng operation but also the extent of movement of plunger 21, may be adjusted. l

A I claim.:-

1. An ignition system for`internal combus- A tion engines, comprising primary and secondary circuits, the primary circuit including a normally closed piston actuated circuit breaker, and the secondary circuit including a spark electrode disposed in a combustion chamber within sparking distance of a wall thereof. p

2., An ignition system for internal combustion engines, comprising primary Vand secondary circuits, the primary circuit includ-- ing anormally closed piston actuated circuit breaker, andthe secondary circuit including a spark electrode disposed in a combustion chamber within sparking distance of a piston.

3. An ignition control'for internal combustion engines, comprising a housing substantially sealed from the combustion chamber over a piston, a spring pressed`plunger extending into the path of the piston, and

circuit terminals disposed in said housing by movement of said head of an engine with .the plunger extending into the path ofa piston.

-5.An` ignition control for internal combustion engines, comprising a threaded nipple having acup-like upper portion, an inverted cup adapted to form with said cuplike upper portion, a sealed housing, a

spring pressed plungersecured in said inverted cup and extending downwardly through said nipple, and make and break contacts within said housing operated by lsaid plunger.

WILLIAM F. HAMn'JroN'.

i lo 

